Welcome!
Sometimes you get denied. It happens to me all the time. Wait a few weeks and try again.
You want to do Chase cards first (if practical.) 5/24 is real enough.
Valuation of the points is important... be sure you are at least getting 1.5cpp (cents per point) on your UR points and maybe 1.3cpp on the United miles. So a $400 flight would cost no more than 25k-30k points. (Examples of much better valuations are usually for business class+.) You can probably do better than that with a $300 domestic United flight, but for the International flight, I would probably just pay with the airline credit card or CSP/R or book the flights through the Chase portal with UR points. That way you still get miles for the flights, and with the CSR you get 1.5cpp. (We leave for Bali in a few weeks, and I just booked those flights through the CSR portal.
For hotels, look at the IHG card and the Bonvoy Boundless. With each of these cards, you can get enough points for a mid-range hotel for 5 nights (5th night free when booked with points.) With his/her cards, you now have 20 free hotel nights.
As an alternative, look at the Venture card. If you book via hotels.com you will get $550+ in hotel credit. For our Bali trip, that got us 4 nights free in a nice resort with breakfast included.
There are links to each of these cards and an example of our Bali flight/hotel here -
https://www.gocurrycracker.com/summer-plans-2019/ )